Enhance new Python Errors

[acbart]

There's a bunch of new enhancements to built-in python runtime and syntax errors. We should do more to support and enhance them.

For example, SyntaxError can now give messages about things like "unterminated string literals". Novices probably don't know what that means.

The exact messages here might need to be parsed and manipulated, or something. They aren't just different errors. We'll need to do a lot of investigating here.

[acbart]

I wonder if we should do enhancements like looking for the substring "string literal" and then just define that term if it's found? Better than trying to regex for exact complicated strings, probably...